Observed chemical abundances of the six N-emitters and comparison samples from the literature. Top: N/O versus O/H. Bottom: C/O versus O/H. CEERS-1019 is shown by a red star, GN-z11 by a blue circle. The z ∼ 2.6 − 3 lensed galaxies: Lynx arc, SMACS2023, and the Sunburst cluster are shown with red, black, and orange crosses, the low-z galaxy Mrk 996 is marked with a green cross (two N/O values from James et al. 2009 for the central region and from the total galaxy). The magenta shaded region and outlined box indicate the range of abundances allowed for GN-z11, according to Cameron et al. (2023a). Low-z star-forming galaxies and HII regions from the compilation of Izotov et al. (2023) are shown by small black symbols. The dash-dotted line shows the average trend observed in low-z star-forming galaxies, as parametrized by Vila-Costas & Edmunds (1993) for N/O and C/O by Dopita et al. (2006), respectively.